High voltage substation



y Oct. 21, 1958 A vlMHQF 2,857,557

HIGH VOLTAGE SUBSTATION .Filed March 8', 1954 4 Sheets-Sheet 1 A .9 Z 49M; F75. 5.

4 INVENTOIL Ha/@50. IMA/ox:

A. lMHOF HIGH VOLTAGE SUBSTATION l Oct. 21, 1958 4 Sheets-Sheet 2 FiledMarch 8; 1954 INVENTOR. 44 FP50 .ZM/fop :www

Oct. 21, 1958 A. lMHoF HIGH VOLTAGE suBsTATIoN 4 Sheets-Sheet 4 FiledMarch, 1954 v /ZO 7a IN V EN TOR.

402250 221f1f/ofc' BY v States Patent HIGH voLrAoa sUBsrArroN AlfredImhof, Zurich, Switzerland, assignor to Moser- Glaser & Co., A. G.,Muttenz, near Basel, Switzerland Application March 8, 1954, Serial No.414,813 Claims priority, application Switzerland March 6, 1953 39Claims. (Cl. 317-9) The invention relates to electric high voltageapparatus, and more particularly to a high voltage apparatus forconnecting lines or bus bars with each other.

It is an object of the present invention to provide a high voltageapparatus of the kind described which forms a completely metal enclosedsubstation.

It is another object of the present invention to provide a high voltageapparatus capable of withstanding voltages of 60 kilovolts or more.

Other objects and advantages of the present invention will becomeapparent from the following detailed description thereof when read inconnection with the accompanying drawings forming part of thisspecification and illustrating, by way of example, some embodiments ofthe present invention. In the drawings:

Fig. l is a sectional view of an embodiment of the coupling meansaccording to the invention;

Figs. 2 to 6 are, respectively, sectional views of other embodiments ofthe coupling means according to the invention;

Figs. 7, 7a, and 8, are respectively, sections of two.

further embodiments of the present invention;

Fig. 9 is a wiring diagram of certain parts shown in Figs. 7, 7a, and 8;

Fig. 10 is a sectional view of still another embodiment of theinvention; and

Figs. ll and l2, are, respectively, sectional views of two moreembodiments of the invention.

Referring now to the drawings, it will be seen that in a substationaccording to the invention syntheticA resins are provided as insulatinglayers between the high voltage parts and the grounded metal enclosure.VFluid insulating materials such as oil or compressed air are used onlyin very limited quantities in coupling joints between solid parts and inducts in which component parts of the apparatus are moving. Each phase'may be enclosed separately, or all phases may be enclosed togetherprovided the voltage is not too high.

The above mentioned synthetic-resin must be of the type which is liquidduring the casting process and hardens without giving off volatilecomponents. Resins that harden at room temperature, as well as thosethat harden at elevated temperatures may be used. The hardening maybeeffected by means of either polymerization or polyaddition. Suitableresins are, for instance, epoxy resins such as those sold in commerceunder the trade name Araldite, which can be cast in liquid form .at 130C. and are set, for instance, at about 120 C.

A fundamental component of a high voltage substation according to theinvention is the electrical coupling between the current carrying busbars. Two diierent ern` bodiments of such a coupling are shown in Figs.1 and 2 Where a bus bar carrying high voltage includes a part 1 and apart 1a connected with each other by a contact tongue 5. The partk 1 isembedded in an insulatorZ consisting of a synthetic resin of the kindreferred to above, and part 1a is embedded in a similar insulator 3consisting also of synthetic resin. Metal coverings 4 and 2,857,557Patented Oct. 2l, 1958 4a are arranged on the outside of the insulators2 and 3, which are separated by a conical joint 6 (Fig. l) or a joint 6(Fig. 2) having a V-shaped cross-section which is lled with a uid oruidized insulating material 'such as a heavy oil, a chlorinatedbiphenyl, a chlorinated phenylidan, a peruoroether such asperfluorohexylether (C6F13)2O, or perfluoro-CB cyclic ether c-CaFlGO, auoro-t-amine such as triperfluoropropylamine (C3F7)3N, a half liquidpolyvinylchloride, a gaseous chlorinated methane of high dielectricstrength, or a compressed gas. Fluorine compounds are in particularsuitable as a dielectric for the joint owing to their high dielectricstrength, stability, heat resistance, noninammability, and high Iboilingpoint.

Since only small quantities of the dielectric are needed in the narrowjoints, even expensive substances may readily be used.

A reservoir 7 containing the fluid insulating material is connectedthrough a pipe 102 having an orice 103 arranged in the ange :1 with acircular chamber 104 forming the outer end of the joint 6. Instead ofproviding separate reservoirs such as 7 for each joint, a centralreservoir or tank may be used, which suppliesv all the joints with thefluid insulating material. By the use of pressure, a complete lling ofall joints with the iluid insulating material can be insured, whichprovides for increased electric strength.

In such a joint coupling, only readily controllable axial electricalforces are set up. Tests of such joints have shown that with smoothjoint walls and transformer oil as the insulating material a creepagegradient of 25 kv./cm. (R. M. S.) and more is attained.

In the embodiment of the invention shown in Fig. 3 the joint 6 is curvedso that the voltage stress along the joint surface is substantiallyconstant. Y

In the embodiment shown in Fig. 4 of the drawings, the joint 6a isformed by interengaging cam surfaces which in cross-section form azigzag line 6a the slopes of which vary, e. g. decrease from theconductor 1 to the metal coverings 4, 4a. In this construction, theaxial length of the joint is shortened in comparison to the joint 6"shown in Fig. 3.

Referring now to Fig. 5 of the drawings, the metal coverings haveconical parts such as 106 and 106a connected along the base flanges 107,107a thereof with one another by screw bolts such as 108. The conicalparts 106 and 106a accommodate, respectively, the conical base portions2a and 3a of the insulators 2 and 3, which base portions each from aplurality of ridges and 10551l and grooves 9 and 9a, respectively. Theridges 10S of the insulator 2a are arranged opposite to the ridges 105aof the insulator 3a so as to increase the creeping path. If the grooves9 and 9a have a depth exceeding a predetermined minimum value thebreakdown of the dielectric will bea puncture of the fluid insulatingmaterial lling the joint 6b and the grooves 9, 9a instead of a ashoveralong the creepage surfaces (e. g. Fig. 5).

However, if desired, the ridges 105 and 105a can be arranged oppositelyto the grooves 9 and 9a, respectively, so as to extend the length of theelectric creeping path.

The joint shown in Fig. 5 allows of a lateral removal of. the couplingIbecause no parts of the solid dielectric of the coupling areinterlocked with the solid dielectric of the apparatus. The contact isshown here by way of example as a pressure contact 8.

Tests have shown that with respect tothe electric strength of thejoints-certain solid dielectrics used as llers, such as polyethylene,behave, when under pressure, similarly to fluid dielectrics proper. Itis, therefore, to be understood that the term Huid dielectrics embracesalso suchgsolid dielectrics which have owing properties, particularlywhen they have a liquid surface film or a surface lm of pastyconsistency. The term equally applies to porous materials, for examplepaper, which are impregnated with a freely owing dielectric, such asoil.

Referring now to Fig. 6 of the drawings, a coupling ac.- cording to thepresent invention is shown which makes it possible to actuate internalparts which are at a high potential by imparting thereto rotary ortranslatory motion by means of screw threads, worm gears Or ,the like.At the outside, the coupling must be provided in this case witharmatures having gliding surface yFor instance, the embodiment shown inFig. 6 includes a revolvable insulator 11 arranged between theinsulators 2 and 3 separated therefrom by joints 6c and 6d,respectively. The insulator 11 may be rotated by a ,rotating shaft 116carrying a worm 14 engaging a worm wheel 13 arranged at thecircumference of a flange 113 of a sleeve 117 having a U-shapedcross-section and being connected with the insulator 11. The outercoverings 4 and 4a of the insulators 2 and 3 have flanges 1 19 connectedby iluid-tight joints 15 with the anges 120 of the sleeve 117- The innerpart 12 of the insulator 11 is threaded and engages a threaded part 121of a rod 10 tov which a high potential is imparted.

The insulator 11 is coupled with the rod 10 by means of the threadedpart 121 engaging the part 12 of the insulator 11 so as to impart to therod 10 translatory motion to and fro in the axial direction of the rod.If desired, the gear connecting the insulator 11 with the rod 10 may bedesigned so as to impart a rotatory motion to the rod 10 about the axisthereof.

In sections having discontinuities in the bus bars, as for example incircuit breakers and disconnecting portions, the bus bar ends must bedesigned in a special manner to avoid an excessive increase of theelectric field strength in thel surrounding insulation. The inventionprovides two solutions to this problem. One solution consists indesigning .the busl bar ends within Spheres or sphere-like electrodes4such as those shown for example in Fig. l0. TheV other solution consistsin the embedding of stress controlling condensers as shown in Fig. 7,which illustrates a complete apparatus according to the presentinvention, the wiring diagram of which is shown in Fig. 9 of thedrawings.

The embodiment shown in Figs. 7 and 7a serves for connecting a highvoltage cable 70S with a bus bar 771 and includes a cable section 701having a termination 708', a coupling member 702 coupling the cablesection 701 with a section 703 being formed as a disconnecting switchmore fully to be described hereinafter, a section 704 including apotential transformer and a current transformer also more fullydescribed hereinafter. The section 704 couples the section 703 with asection 705 including a circuit breaker, an auxiliary coupling member706 coupling the circuit breaker section 705 with a section 703'similark to section 703. and being formed as a disconnecting switch, anda section 797 connecting the section 703 with the bus bar '771.

Section 703 being formed as a disconnecting switch comprises twospherical or almost spherical electrodes 709 and 710 embedded into thesolid dielectric 721, or 721a, 723 and forming, respectively, the endsoffhollow cylindrical switch members 711 and 712 which may be eitherelectrically connected or disconnected by a metal contact rod 713arranged for longitudinalmotion in a channel. 714 extending from thetermination 7,08' through the hollow cylindrical metal member 711 to thehollow electrode 710. The channel 714 is filled with a fluid dielectricsuch as air or heavy oil. The rod 713 ,can be axially displaced, forexample electromagnetically, under the action of a spring (not shown) orby a servomotor 715 the shaft 715 of which is engagedrby a rack 713sformed on the rod 713. The 'servo-motor is connected to the secondary717 of an insulating transformer having an iron core 716 and a primarywinding 718, so

`that the servo-motor 715 is supplied with the high secl ondary voltageof the insulating transformer 7 16,7178

. grounding rod (not shown) may be pushed as far as the axis of thedisconnecting switch through a channel 719 arranged at right angles tothe axis so that a creepage path leads from the disconnecting switch toground.

Alternatively, the disconnecting switch may comprise two rods (notshown) making contacts with each other in lthe middle of the channel 714and moving in opposite direction when the disconnecting switch is to beopened. In such a disconnecting switch, the one half is identical withsection 703 of Fig. 7, the other half is the mirror image of said firsthalf. In Vthis way, the disconnecting switch possesses two sphericalelectrodes 709, each pro-v vided with a s ervomotor 715 for controllingthe contact rods 7.13. Each servomotor is supplied from an insulatingtransformer 716-718 as set forth hereinabove.

Section 704 includes a bus bar 738 embedded in an insulator 737consisting of synthetic resin and enclosed by a metal covering 740b.connected, respectively, withl the metal coverings 703b and 705b ofswitches 703 and 70,5 by screws such as 7.04. Embedded in the insulator'737 are the Vprimary winding 739 and the secondary winding 7,40 of apotential transformer having an iron core 741 being partly outside themetal covering 704b and the insulator 737. Also iron cores 742 and 743of current transformers are arranged so as to surround the bus bar 738forming the primary winding thereof, whereas the secondary windings74251 and 743a of the current transformers are embedded in the insulator737.

Section 705'is a circuit breaker section comprising two contact rods'727 and 723 arranged opposite to each other in a 4channel 724 filledwith compressed air, and connected, respectively, to the bus bar 733 anda hollow electrode 726 formed as body of revolution about an axisvcoinciding with the common axis line of the rods 727 and 728, yof whichrod 727 is stationary whereas the rod 728 is arranged for translatorymotion and actuated by a compression spring 729 acting on a piston 730so as to close the circuit breaker including the contact rods 727 and728. The circuit breaker opens its contact when air is applied to thepiston 730 overcoming the force of the' spring 729; on displacement,said piston opens a connecting channel to the hollow electrode 726 andallows thc compressed air to enter said electrode. The arc between thecontact rods 727 and 72S is confined to a narrow section 737 of thechannel 72.4. If desired, the circuit breaker may be equipped withmultiple contacts (not shown) and a plurality of arc coniining sectionsplaces in series to one another.

Compressed air is'supplied to the circuit breaker over a channel 732traversing the insulating wall 705C andy provided with valves 732a and732b at the ends thereof., to a chamber 725 surrounding part of thestationary rod 727 and communicating with the channel 724. The thicknessof the insulating well 705e depends on the voltage against ground of thestationary rod 727 so as to obtain a suitable flashover voltage; Thevalves 7320 and 73211 are designed as check valves ensuring that the`chamber 725V and the channel 732 are filled ,by compressed air. Y

The hot gases emitted by the opening arc between the rods 727V and 728escape at a high velocity into the hol low electrode 726 having astrongmetal wall in order to take up rapidly a considerable portion ofthe heat developed by,A the hot Agases which escape slowly to theatmosphere through the channel 734 provided at its ends withcheclcvalves Y733; The valve arrangedat the enA tranc'eof'the channel734 is designed so as to open 'slowly Aunder the influence of theincreased pressure prevailing within the air chamber formed by thehollow electrode 726, in which the lrot air can be cooled. Thisisnecessary since hot air has a low dielectric strength so that somedamage might be done to the insulating wall. Circuit breakers subject tovery high voltages require stress controlling condensers such as 735connected in series and embedded into the insulating material so as tosurround the air channels 734.

The closing of the circuit breaker is accomplished by suitable devices(not shown) which are well known in the art.

The hollow electrode 726 is continued by another hollow electrode 736abeing rigidly and electrically connected with a metal rod 760 arrangedfor making contact with the ycontact rod 713 forming part of the section703', which is a disconnecting switch similar to the disconnectingswitch formed by section 703 so that no detailed description thereof isdeemed necessary.

As will be seen from Figs. 7 and 7a, all sections 702-707 comprise,apart from the current-carrying membersv thereof, insulator 70211 andmetal coverings 702b which are the analogs of the insulators 2, 3 andthe metal coverings 4, 4a described hereinbefore. The insulators consistof synthetic resin and some of the insulators, for instance thosearranged in the section 703, are provided with a channel 719 forallowing the entry of gases or liquids or of solid members such as rodsor cables to be applied between ground and the high volta'ge currentcarrying rod 713. a continuous insulating surface from the groundedmetal coverings to the inner parts such as 713 which are at highvoltage. r

The inner parts of the various sections 703-703 may be assembled, takenapart, or checked as follows: The two spherical orgnearly sphericalbodies 709 and 710 of section 703 are removable to allow replacement ofcontacts (not shown) or access lto the servo-motor 715 arranged withinthe body 709. In order to accomplish this, a cylindrical body 721consisting of synthetic resin is separated from the body 721a by a joint720 filled completely with a fluid insulating material, and the bodiesV721 and 72la are detachably secured together. The same applies to thecylindrical body 723 which is separated from the body 721a by a joint722.

An alternate assembling and disassembling procedure will be explainedwith reference to sections 705 and 706. In order to render accessiblethe inner parts'of section 705, the coupling member or section 706 isremoved so that the opening 736 becomes accessible, thus giving accessto the inner parts of section 705 more fully described hereinbefore. v

As set forth hereinabove, the operation of circuit breaker contacts ordisconnecting contacts and of other partsconnected to high voltage mayeasily be secured by the revolvable joints mentioned hereinbefore, or bymeans of embedded electromagnets or servo-motors such as 715, for whichthe voltage may be supplied by a low voltage network (not shown) bymeans of servo-transformers such as 716-718 which are embedded in theinsulators 721a.

Most of the apparatus belonging to a section such as disconnectingswitches, transfer switches, current transformers, potentialtransformers, circuit breakers, etc., are designed in such a manner thatthey may be mounted directly in line with the bus bar which is arrangedso as to be approximately in line with the longitudinal axis of theapparatus. Embodiments of such a design have been explainedVhereinabove. l

In order to keep the distances of the phases from one another as shortas possible, all parts protruding at right angles touthe axis of thesystem such as the part 732 should be arranged so that they protrude inone and the same .direction which shouldr be perpendicular to the planeconnecting the bus bars of neighboring phases.

These channels provide Referring now to Fig. 8 of the drawings, acomposite bus bar is shown connecting a cable 808 with a bus bar 871,said part being the analogue of the cable 708 and the bus bar 771 shownin Fig. 7, and including sections 802, 803, 804, 805, 806, 803 and 807being the analogue, respectively, of sections 702, 703, 704, 705, 706,703 and 707 of Fig. 7 so that a detailed description of these sectionsis deemed unnecessary. However, whereas in the arrangement shown in Fig.7 all the sections are aligned with one another, in the arrangementshown in Fig. 8 the sections'802-804 are aligned and the same applies tosections S05- 807 in the reverse direction. Two,

sections 812 and 818 are interrelated in series between sections 804and805. One of these sections, viz. section 818 comprises a bent metalcover 820 connected to thev grounded covers 821 and 822 of sections 812and 805, respectively, an insulating body 823, and a bus bar segment 824being electrically connected with the bus bar element 838 forming partof section 804 and the rod 827 forming part of the circuit breakersection 805. The

bus bar segment 824 is curved so as to align smoothlywith the bus barelement 838 and the rod 827.

In Fig. l0 a so-called transfer switch is shown byv which an incomingline (not shown) is connected to one of two.conductors (not shown). Theincoming line is held by a clamp 1021 arranged in the upper part of aspherical electrode 1003 and connected by a flexible connection (notshown) to a contact rod 1006 provided with a rack 1006a being inengagement with a worm 1008a driven by a servo-motor 1008 fed by thesecondary 1011 of a transformer having an iron core 1010 and a primarywinding 1012, so that the contact rod 1006 can be displaced in axialdirection within the channel 1007 provided in the insulating body 1001.The channel 1007 ends to the left and to the right, respectively,

terial as the insulating body 1001 from which they arey separated by thejoints 1024 and 1025, respectively.

The insulating body 1001 is preferably provided with channels such as1009 and/or 1009 which are arranged symmetrically at either side of thetransformer 1010- 1012 and receive grounding rods (not shown). Agrounded metal covering 1030 is provided at the outside of the transferswitch.

In operation, the contact rod 1006 is either kept in its left-mostposition as shown in Fig. 10 where it makes contact with the metalsleeve 1005, or in the right-most position (not shown) where it makescontact with the sleeve 1004, so that the incoming line (not shown)connected to the contact rod 1006 is alternately connected to theconductors (not shown) which are connected, respectively, with the metalsleeves 1005 and 1004.

In the embodiment shown in Fig. ll of the drawings, a disconnectingswitch is shown which comprises a stationary portion 1100 and a movableportion 1101. y The stationary portion includes two metal rods 1111 and1112 aligned with one another and ending in cup-shaped contacts 1106 and1116, respectively, arranged in spaced relationship parallel to eachother. The rods 1111 and 1112 andthe cup-shaped contacts 1106 and 1116are embedded in an insulating body 1104 consisting of a synthetic resinof the type described hereinbefore and having two cup-shaped cavities1120 and 1121 arranged parallel gaging thel correspondingly shaped endportions (not shown) of other circuit elements (not shown).

vThe movable portion 1101 includes a U-shaped metal` d. 1.1.0.3, theendsof which are adapted to make contact with the cup-shaped contacts 1106and 1116 of thel stationary portion 1,100. The U-shaped rod 1103 isembedded except at its ends ina U-shaped insulating body 1106 havingconical end portions such as 1130 iittirig into the cavities 1120 and`1121. A metal covering 1128 encloses the main portion of the U-shapedinsulating body 1105 so as, to make contac twhen the disconnectingswitch is, closed, with the grounded metal covering 1123 of thestationary portion 1100 and to form a continuation thereof.

Fig. ll shows the disconnecting switch with the portions 1100 and 1101thereof in closing position for connecting the metal rods 1111 and 1112through the U- shaped metal rod 1103, For opening the disconnectingswitch, the movable portion 1101'` is pulled out of the cup-shaped'cavities 1120, 1121, so that the ends of the U-shaped metal. rod 1103,`are. removed from the cupshaped contacts 1 106 and 1116.k

' If it is intended to use the disconnecting switch shown` in4 Fig. 1lin. a very high voltage` circuit, the insulating stress within theinsulating bodies 1104 and 1105 should be, controlled by stresscontrolling condensers (not shown) analogous to the stress controllingcondensers 735 shown in Fig. 7a.

Referringrnow to, Fig. 12, it will be seen that the disconnecting switchshown in this iigure is similar to that shown in Fig. 1,1 and thatespecially the parts 1204, 1206, 12071207a, 1211, and 1212 thereof havethe same function, respectively, as the parts 1104, 1106, 1107, ll07a',1111, 1112 shown in Fig. l1. However, in the embodiment shown in Fig. l2a potential transformer and a` current transformer havey been added. Thepotential transformer includes an iron core 121.0 partly embedded inthe,Y insulating body 1204, a primary winding 1208 and secondarywindings 1209; The current transformer inciudcs'an iron core 1213,51primary winding 1221, and asecondaryv winding 1222. lt should be notedthatthe transformers are arranged symmetrically at one and theother-'side of the middle plane A-A of the disconnecting switch.

The overvoltage or lightning arresters used in my apparatus do not,differ in principle from the conventional porcelain clad arresters butare also designed for complete metal enclosure in the manner describedfor the other parts of the apparatus. The arrester is tightly surroundedby an insulating wall of insulating resin of the type herein describedand insulated by said wall from the metal covering. The insulating wallbetween the active arrester part and said earthed metal covering has a`gradually decreasing thickness from the entrance bush* ing towards thegrounded end.

In another form, the arrester is of the straight line type, that is, thehigh voltage bus bar lies in the axis of the arrester, which is built asa solid of revolution. The

coordinating spark gaps, the voltage dependent resistorsV andv thecurrent limiting resistors are built into coaxial cylindrical bodies.

The following description concerns the actual installation of'such astation. Three arrangements are particularly suitable:

(l) The devices and their bus couplings are placed on a horizontal track(not shown). They are equipped with wheels and can therefore be readilymoved during the assembly or disassembly of an in-line station. Anexample of such as assembly is shown in Fig. 7, in which the rails andWheels have been omitted. lf the bus bars run. vertically and areperpendicular to the station axis, the incoming lines need not have anoffset. The individual pieces ofJ equipment are described hereinabove.

(2) The devices are mounted on one side of a vertical carrier (notshown). Each individual part can be moved along the vertical axis. Forexample they could be fastened to acommon screw. spindle (not shown) inorder to be able tochange their position through rotation ofthe 8spindle. If the, bus bars are horizontah the incoming lines need nothave an offset.

(3) The devices. are mounted on both sides of a vertical carrier, so asto form together a U-shape. If the bus bars run horizontally, theincoming lines need not have an offset. This arrangement is shown inFig. 8.

in all three arrangements, thei various phasesA of an nphase system canbe mounted so closely to one another that the longest axialprotrusionstouch each other.

Inv order tov carry out the principle of. the complete metal enclosurethe incoming high voltage lines must also be metal enclosed and enterthrough cables which are completely metal clad'A at the station endofthe cable terminal.

If solid dielectrics are used as lillers of the coupling joints, forinstance in form. of sheets,v the surface of such. solid dielectrics canbe moistened with one of the insulating liquids recitedhereinabove inorder to insure a perfect contact between the synthetic resin and the`solid joint filler. For the. same purpose also salve-like substances orinsulating salvescan be used, as for example a silicone paste or`solvents, which, applied to the surface of, solid dielectric, softensaid. surface and make it sticky.

What I claim is:

l. A highvoltage substation comprising a plurality of metal clad,electrically connected high voltage devices mechanically coupled forready removal and replacement. of individual devices, each of4 saiddevices comprising a.A form-stable insulating block of a syntheticresin, anelectric conductor firmly and substantially completely embeddedin said block, and an. outer metal covering, said. insulatingblocksbeing joined together plugwise to form. a susbtantially continuousinsulation leaving only nar.- row gaps betweentheadjoining ,facesof saidblocks, and

' said metalr coveringsv forming a, grounded metalV sheath4 enclosingthe substation, said gaps being filled. with an insulatingmaterialhaving flow properties.

2. A substation as deiined in claim l wherein said synthetic resin is anepoxy resin.

3. A substation as defined in claim l wherein said adjoining ends ofsaid insulating blocks form conical socket joints.

4. A substation as defined in claim l wherein the adjoining endsoftheinsulating blocks are curved to ensure a constant voltage stressalong-v the joint surface.

5. A high voltage substation as defined in claim l, wherein the surfacesof said insulating blocks enclosing said gaps have a configurationincreasing the length of the creepage path.

6. A substation as defined in claim lV comprising joints having azig-zag' profile.

7. A substation as defined in claim l. comprising insulating bodieshaving straight end faces so as to allow removal of said bodiesperpendicularly to the axis of the substation.

8. A substation as defined in claim 1 comprising grooved joints of theinsulating bodies, the ridges of said grooves being arrangedoppositeeach other.

9. A substation as defined in claim l comprising insulating bodieshaving opposite grooved end faces interengaging cach other to form saidjoints.

l0. A substation as definedin claim l wherein said joint-iil-linginsulating material has flowing properties under pressure.

1l. Asubstation as defined in claim l wherein thejointfillinginsulatingv materialk is a thermoplastic substance having owingproperties underV pressure.

l2. A substation as defined` in, claim l includingV means placing thejoint-filling insulatingfmaterial underv pressure,

13. A substation as defined in claim 1 comprising` a'- assise?oint-filling insulating material is a porous solid impregnated with aliquid dielectric.

15. A substation as defined in claim 1 wherein said insulating bodiesare composed of separate portions and the joints between said portionsare filled with an in sulating material having flowing properties.

16. A substation as defined in claim l comprising an insulatingtransformer embedded in said continuous insulation and supplyingelectric energy to at least part of said high voltage devices.

17. A substation as defined in claim 1 wherein a plurality of saiddevices is designed as in line devices having a current conductorarranged approximately in the axis of said devices.

18. A substation as defined in claim 1 comprising a plurality ofprotruding parts, all said parts protruding at right angles to a planethrough the axis of a neighboring substation in the same direction.

19. A substation as defined in claim 1 comprising high voltage deviceshaving at least one hollow electrode, a duct connecting said electrodesto the outside, and a plurality of condensers embedded in saidinsulating bodies and surrounding said ducts, said condenserscontrolling the voltage gradient of said electrodes.

20. A substation as defined in claim 1 comprising a disconnecting switchforming part of said substation, said disconnecting switch having twospaced spherical terminals embedded in solid dielectric, a straightchannel in the axis of said terminals, a fiuid dielectric in saidchannel, and a metal rod arranged for translatory motion in saidchannel.

21. A substation as defined in claim comprising in the symmetry plane ofsaid spherical terminals a second channel leading perpendicularly fromsaid straight channel to the metal enclosure, said second channel beingarranged for receiving a grounding electrode in the open position and auid dielectric in the closed position of said disconnecting switch. v

22. A substation as defined in claim l comprising a circuit breakerdesigned as a metal enclosed compressed air breaker, said circuitbreaker having an insulation to ground consisting primarily of embeddingresin, two opposite hollow substantially spherical electrodes and acompressed air channel connecting said electrodes embedded in saidresin, two contact rods in said channel, one of said contact rods beingstationary and the other contact rod being arranged for translatorymotion, and additional channels for admitting compressed air anddischarging the air contaminated by the arc between said contact rods,and means to close said additional channels so as to maintain the airunder pressure.

23. A substation as defined in claim 22 comprising an air chamber forreceiving the hot air from said arc and discharging said air at lowertemperature through said additional channels to the outside.

24. A substation as defined in claim l comprising bus bars and transferswitches, said transfer switches having three substantially sphericalterminal electrodes, tw-o of said electrodes serving as ends of the busbars, the third of said electrodes serving as the end of the line to beswitched and a plurality of contact rods forming part of said devicesand being movable in translatory motion towards either one of said twoelectrodes by means of a servo force.

25. A substation as defined in claim 1 comprising a disconnecting switchin the form of a U-shaped plug having movable terminals and convexinsulators, the axes of said insulators receiving said movable plugs.

26. A substation as defined in claim 25 wherein said disconnectingswitch has a stationary part containing an instrument transformerembedded therein.

27` A substation as defined in claim 1 including a lightning arresterhaving an entry end and a grounded end and being embedded in anenclosure of synthetic resin, the wall thickness of said enclosuredecreasing from the entry end to the grounded end.

28. A substation as defined in claim 1 including a lightning arresterformed a's a solid of revolution, and a bus bar in the axis of saidlightning arrester.

29. A substation as defined in claim 1 comprising wheels at the devicesand couplings of the station and horizontal rails supporting saidwheels.

30. A substation as defined in claim 1 comprising vertical bus bars.

31. A substation as defined in claim 1 comprising horizontal bus bars.

32. A substation as defined in claim 1 comprising a vertical support,one side of said support carrying the parts of the substation, andvertical threaded spindles for displacing said parts.

33. A substation as defined in claim 1 comprising a vertical supportcarrying the parts of the substation on both sides in form of a U.

34. A substation as defined in claim 1 including cables for the incomingand outgoing high voltage lines, the station and terminals -of saidcables being fully metalenclosed.

35. A substation as defined in claim l wherein at least part 0f saidelectrical conductors are bus bars having approximately sphericalterminals.

36. A high voltage substation as defined in claim 1, comprisingrevolvable members coupling said high voltage devices, means foractuating said revolvable coupling members from the outside, and meanstransmitting the rotary motion of said coupling members into translatorymotion of said high voltage devices.

37. A high voltage substation comprising a plurality of metal clad,electrically connected high voltage devices mechanically coupled forready rem-oval and replacement of individual devices, each of saiddevices com prising a form-stable insulating block of asynthetic resin,an electric conductor firmly and substantially completely embedded in-said block, and an outer metal covering, said insulating blocks beingjoined together slugwise to form a substantially continuous insulationleaving only narrow gaps between the adjoining faces of said blocks, andsaid metal coverings forming a grounded metal sheath enclosing thesubstation, said gaps being filled with an insulating fluid.

38. A substation as defined in claim 37, wherein said fluid insulatingmaterial is a member of the group consisting of fluoroethers,fluoro-t-amines, and phenylindan.

39. A high voltage substation comprising a plurality of metal clad,electrically connected high voltage devices mechanically coupled forready removal and replacement of individual devices, each of saiddevices comprising a form-stable insulating block of a synthetic resin,an electric conductor firmly and substantially completely embedded insaid block, and an outer metal covering, said insulating blocks lbeingjoined together plugwise to form a substantially continuous insulationleaving only narrow gaps between the adjoining faces of said blocks, andsaid metal coverings forming a grounded metal sheath enclosing thesubstation, said gaps filled with air under pressure.

References Cited in the file of this patent UNITED STATES PATENTS2,089,052 Calvert Aug. 3, 1937 2,518,665 Collard Aug. 15, 1950 2,588,436Violette Mar. 11, 1952 FOREIGN PATENTS 575,511 Great Britain Feb. 21,1946

